1. Field of the Invention
The present invention relates to a nebulization structure, in particular to the nebulization structure that uses a nebulization plate and a piezoelectric annular plate in a nebulization process.
2. Description of the Related Art
As science and technology advance and consumers have increasing higher requirements on a light, thin, short and compact design of various different products, different technical areas including medicine, bio-tech, computer technology, printing or energy industry tend to develop products with a fine and miniaturized design.
With reference to FIGS. 1, 2 and 3 for an exploded view, a perspective view and a cross-sectional view of a conventional nebulization structure respectively, the nebulization structure 1 is installed on a side of a cavity 14 and comprises a piezoelectric annular plate 11, a nebulization plate 12 and a structure annular plate 13. Wherein, both sides of the nebulization plate 12 are packaged and fixed between the piezoelectric annular plate 11 and the structure annular plate 13. The structure annular plate 13 is provided for fixing the nebulization plate 12 and oscillated by the piezoelectric annular plate 11 to vibrate together with the piezoelectric annular plate 11.
When an electric field is applied to the piezoelectric annular plate 11 from the lateral side of the piezoelectric annular plate 11, the piezoelectric annular plate 11 produces a transverse contraction and induces the deformation of the nebulization plate 12 to link the nebulization plate 12 and deform accordingly. Since the piezoelectric contraction produced by the piezoelectric annular plate 11 and the deformation of the nebulization plate 12 vary, the nebulization plate 12 of nebulization structure 1 is induced a curved movement to produce up and down oscillations of the nebulization plate 12.
When the operating frequency of the piezoelectric annular plate 11 is exactly equal to the vibration frequency of the overall structure, spray holes 121 formed on the nebulization plate 12 produce a very high speed of a spray, so that the inertia force of droplets formed on the spray holes 121 of the nebulization plate 12 is greater than the surface tension of the spray holes to spray micro droplets from the spray holes in order to achieve a fluid nebulization effect.
Since metal has a better effect of transmitting the vibration energy, the conventional nebulization plate 12 is generally made of a metal material. Due to the limitation of the metal material, the metal nebulization plate 12 may become fatigued, embrittled, or gradually weaken in the oscillation effect easily to result in cracking the nebulization plate 12, after the nebulization plate 12 has been operated at a high frequency oscillation for a long time.
If the nebulization plate 12 is made of a polymer material instead, the drawbacks of the metal nebulization plate 12 can be overcome, but the polymer material has a loosened structural arrangement of molecules and an insufficient rigidity, the efficiency for the nebulization plate to receive the energy transmitted from the piezoelectric driving element becomes too low, so that the nebulization plate fails to transmit the vibration energy and results in a poor nebulization effect.
In addition, the conventional structure annular plate 13 is an annular structure, so that when it is combined with the piezoelectric annular plate 11 and the nebulization plate 12 to form a nebulization structure, most of the vibration energy produced by the piezoelectric annular plate 11 can only be transmitted to the nebulization plate 12 which is relative to the inner side of the structure annular plate 13, and thus causing the vibration energy failing to be transmitted to the center position of the nebulization plate 12 effectively. As a result, the center position of the nebulization plate 12 cannot be oscillated effectively, and the nebulization effect becomes low.